Update gems to work with Ruby 2.2+

This is what is running on the server now.

Gemfile.lock

@@ -1,9 +1,9 @@
 GIT
   remote: https://github.com/lazyatom/a2_printer.git
-  revision: 11c223b39695a04fe1246711356fa4d510dda47b
+  revision: 20c6db571bbd1e4cb322c4b892b6105ab6d839d0
   specs:
-    a2_printer (0.1.0)
-      serialport (~> 1.0.4)
+    a2_printer (0.2.0)
+      serialport (~> 1.3)
 
 GIT
   remote: https://github.com/lazyatom/recap.git
@@ -82,12 +82,12 @@ GEM
       dotenv (~> 0.11.1)
       thor (~> 0.19.1)
     highline (1.6.21)
-    json (1.7.7)
+    json (1.8.6)
     json_pure (1.7.7)
-    kgio (2.8.0)
-    metaclass (0.0.1)
+    kgio (2.11.1)
+    metaclass (0.0.4)
     minitest (5.10.1)
-    mocha (0.13.2)
+    mocha (1.3.0)
       metaclass (~> 0.0.1)
     multi_json (1.6.1)
     net-scp (1.2.1)
@@ -119,7 +119,7 @@ GEM
       trollop (~> 1.16)
     rmagick (2.13.2)
     sass (3.2.6)
-    serialport (1.0.4)
+    serialport (1.3.1)
     sinatra (1.3.5)
       rack (~> 1.4)
       rack-protection (~> 1.3)